# ARTS built-in documentation server

## Workspace Method iySurfaceRtpropAgenda

### Description

Interface to surface_rtprop_agenda for iy_surface_agenda. This method is designed to be part of iy_surface_agenda. It determines the radiative properties of the surface by surface_rtprop_agenda and calculates the downwelling radiation by iy_main_agenda, and sums up the terms as described in AUG. That is, this WSM uses the output from surface_rtprop_agenda in a straightforward fashion.

**Authors: **Patrick Eriksson

### Synopsis

iySurfaceRtpropAgenda( | iy, diy_dx, surface_skin_t, surface_los, surface_rmatrix, surface_emission, iy_transmittance, iy_id, jacobian_do, suns_do, atmosphere_dim, nlte_field, cloudbox_on, stokes_dim, f_grid, rtp_pos, rtp_los, rte_pos2, iy_unit, iy_main_agenda, surface_rtprop_agenda ) |

### Variables

OUT | iy | (Matrix) | Monochromatic pencil beam radiance spectrum. |

OUT+IN | diy_dx | (ArrayOfTensor3) | Derivative of iy with respect to retrieval quantities. |

OUT | surface_skin_t | (Numeric) | Surface skin temperature. |

OUT | surface_los | (Matrix) | Downwelling radiation directions to consider in surface reflection. |

OUT | surface_rmatrix | (Tensor4) | The reflection coefficients for the directions given by surface_los to the direction of interest. |

OUT | surface_emission | (Matrix) | The emission from the surface. |

IN | iy_transmittance | (Tensor3) | Transmittance to be included in iy. |

IN | iy_id | (Index) | Identification number of iy. |

IN | jacobian_do | (Index) | Flag to activate (clear-sky) Jacobian calculations. |

IN | suns_do | (Index) | Flag to activate the sun(s). |

IN | atmosphere_dim | (Index) | The atmospheric dimensionality (1-3). |

IN | nlte_field | (EnergyLevelMap) | The field of NLTE temperatures and/or ratios. |

IN | cloudbox_on | (Index) | Flag to activate the cloud box. |

IN | stokes_dim | (Index) | The dimensionality of the Stokes vector (1-4). |

IN | f_grid | (Vector) | The frequency grid for monochromatic pencil beam calculations. |

IN | rtp_pos | (Vector) | Position of a radiative transfer point. |

IN | rtp_los | (Vector) | Line-of-sight at a radiative transfer point. |

IN | rte_pos2 | (Vector) | A second geographical position to define the geometry for radiative transfer calculations. |

IN | iy_unit | (String) | Selection of output unit for radiative transfer methods. |

IN | iy_main_agenda | (Agenda) | Agenda calculating the single monochromatic pencil beam spectrum. |

IN | surface_rtprop_agenda | (Agenda) | Agenda providing radiative properties of the surface. |